title: Tetrapod nanocrystals as fluorescent stress probes of electrospun nanocomposites.
abstract: A nanoscale, visible-light, self-sensing stress probe would be highly desirable in a variety of biological, imaging, and materials engineering applications, especially a device that does not alter the mechanical properties of the material it seeks to probe. Here we present the CdSe-CdS tetrapod quantum dot, incorporated into polymer matrices via electrospinning, as an in situ luminescent stress probe for the mechanical properties of polymer fibers. The mechanooptical sensing performance is enhanced with increasing nanocrystal concentration while causing minimal change in the mechanical properties even up to 20 wt % incorporation. The tetrapod nanoprobe is elastic and recoverable and undergoes no permanent change in sensing ability even upon many cycles of loading to failure. Direct comparisons to side-by-side traditional mechanical tests further validate the tetrapod as a luminescent stress probe. The tetrapod fluorescence stress-strain curve shape matches well with uniaxial stress-strain curves measured mechanically at all filler concentrations reported.
authors.affiliation: Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
authors.forename: Shilpa N
authors.initials: SN
authors.lastname: Raja
authors.forename: Andrew C K
authors.initials: AC
authors.lastname: Olson
authors.forename: Kari
authors.initials: K
authors.lastname: Thorkelsson
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Luong
authors.forename: Lillian
authors.initials: L
authors.lastname: Hsueh
authors.forename: Guoqing
authors.initials: G
authors.lastname: Chang
authors.forename: Bernd
authors.initials: B
authors.lastname: Gludovatz
authors.forename: Liwei
authors.initials: L
authors.lastname: Lin
authors.forename: Ting
authors.initials: T
authors.lastname: Xu
authors.forename: Robert O
authors.initials: RO
authors.lastname: Ritchie
authors.forename: A Paul
authors.initials: AP
authors.lastname: Alivisatos
mesh_terms: D019187:Cadmium Compounds / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D045663:Quantum Dots; D018036:Selenium Compounds / Q000737:chemistry*; D013440:Sulfides / Q000737:chemistry*
chemical_list: D019187:Cadmium Compounds; D005456:Fluorescent Dyes; D011108:Polymers; D018036:Selenium Compounds; D013440:Sulfides; C034939:cadmium sulfide; C058667:cadmium selenide